metabolism and nutrition: part 1, 2, 3

Question 1

what is metabolism?

Answer 1

Metabolism is the sum of all the physical and chemical changes that occurs in a living organism.

Question 2

what is a catabolic reaction?

Answer 2

A catabolic reaction is the breakdown of large molecules into smaller molecules.

Question 3

What is an anabolic reaction

Answer 3

An anabolic reaction is the synthesis of larger molecules from smaller ones.

Question 4

what is a macromolecule?

Answer 4

A macromolecule is a large nutritional componets of the diet and inculde proteins, carbohydrates and lipids. They are required in relatively low quantities.

Question 5

What is a micronutrient?

Answer 5

vitamins and minerals that are required in small quantities.

Question 6

Whats an enzyme?

Answer 6

An enzyme is a biological catalyst.

Question 7

what is an isoform?

Answer 7

An isoform has the same fucntion but different amino acid sequence

Question 8

Explain the breakdown of crabohydrates?

combined knowlege including block 3

Answer 8

Lingual amylase
Pancreatic amylase( duodenum)
Dissacharide
Maltose, Sucrose, Lactose
Sugar breakdown (enzyme) (enterocyte jejunum)
Galatose, Fructose, Glucose
Galactose and Glucose use a sodium symporter to enter enterocyte( facilitated transport).
Fructose uses glut 5 transporter (facilitated transport).
Once inside they all use the glut 2 transporter to leave the cell and enter the blood vessel.
THEY ARE THEN TRANPORTED TO LIVER VIA HEPATIC PORTAL VEIN
na ion leaves the cell via a k+/Na+ proton pump. ( active transport)

Question 9

what happens to the glucose in the blood?

Answer 9

Glucose in the blood enters the the body cells where needed and is then its stored in the liver or muscle cells as glycogen. The brain has a obligatory requirment for glucose.

Question 10

whats the max the liver and muscle can store glucose?

Answer 10

100g liver

350g muscles

Question 11

what hormone is relseased and by what organ to help with the entry of glucose into cells?

Answer 11

insulin is released by the pancreas to help with the entry of glusose into cells. produced by beta cells

Question 12

what is (internal) respiration?

Answer 12

(internal) respitration is the breakdown of glucose to synthesis ATP which is an enrgey source needed to drive metabolic process.

Question 13

How much ATP is sythesised by the end of respiration?

Answer 13

32 ATP molecules

Question 14

what is glycolysis?

Answer 14

glycolysis is the breakdown of glucose.

Question 15

explain the process of glucose break down up to the citrate cycle? (aerobic repiration)

Answer 15

glycolysis occurs in the cytoplasm to form two pyruvate molecules.
2x pyruvate molecues enter the mitochondria into the mitochondrial martix.
Link reaction( one molecule at a time)- pyruvate is decarboxylated and dehydragenated leading to a NADH being formed. Acetate then combines with the co-enzyme a to form acetyl co-enzyme.
citric cycle- co-enzyme a leaves and citrate remains and enters the cycle.
de
na
de
na
a
fa
na
citrate is the reformed.

Question 16

where do the products of the citrate cylce then go?

Answer 16

The products then enter the electron transport chain- where they release an electron that is then carried by electron carrier proteins.This releases energy and h plus ions are pumped out into the space creasing a concentration gradient. they then move back in and produce atp.

Question 17

what is the differnce between aerobic and anaerobic respiration?

Answer 17

aerobic repiration uses oxygen

anaerobic repiration lacks oxygen

Question 18

what is gluconeogenesis?

Answer 18

Gluconeogenesis is the synthesis of glucose from lactate, glycerol and amino acids

Question 19

what enzyme is needed in glycolysis in the cytoplasm?

Answer 19

Hexokinase is the essenntial enzyme needed for glycolysis.

Question 20

what happens when the maximum glucose storage is reached in the muscle and liver?

Answer 20

glucose is converted into a lipoprotein by the hepatic cellls and transported to the adipose tissue for storage.

Question 21

How does a lipoprotein form from glucose?

Answer 21

glucose is broken down into puyruvate and then acetyl coA. some glucose is broken down to form glycerol.
acetyl coA is then used to form cholestrol and fatty acid. the glycerol, cholesterol and fatty acid combine to form a low density lipoprotein. which is packaged and sent to the adipose tissue for storage.

Question 22

how do lipoproteins enter into cells?

Answer 22

lipoprotein lipase is an enzyme that faccilitates the entry of lipoproteins into the cell.

Question 23

At what level is blood glucose levels maintained at?

Answer 23

blood glucose level is maintained at 5.5mm

Question 24

How does the body respond to no glucose in the body using fats ?

Answer 24

lipoproteins which are fopund in the blood and fatty acids (which is released by a hormone sensetive lipase in the adipose tissue) are used to form ATP.

Question 25

How does the body use fats to synthesis ATP?

Answer 25

lipoprotein in the blood enter hepatocytes using lipoprotein lipase. fatty acids enter into cell by binding to albinum protein which allows their entry into the cell.
once in the cell they enter the mitochondria and undergo a process known as beta oxidation.betaocidation results is a fatty acetyl which is the converted to acetyle COA. acetyle coa is then used to synthesis atp directly or to form ketone bodies.

Question 26

what are the three main ketone bodies?

Answer 26

acetate
acetoacetate
hydroxybutanyl

Question 27

properties/ characteristics of ketone bodies?

Answer 27

They are water soluble so easily tranported.
They have a sweet smell- so when breathed out they can be smelt.
They can be passed out through urine

Question 28

how are ketone bodies used?

Answer 28

ketone bodies can be broken down into acetyl coa and then used to form atp. its can be used by the brain in the absence of glucose.

Question 29

what products are formed during anaerobic respiration?

Answer 29

During anerobic repiration glucose is broken down into pyruvate in the cytoplasm using the enzyme hexokinase.
puyruvate is then broken down into lactate and h20

Question 30

What happens to the lactate produced after anaerobic respiration has occured and why.

Answer 30

lactate is toxic so it needs to be converted back into puyruvate. and this is done using the cori cycle.

Question 31

explain the metablosim of proteins?

Answer 31

proteins are broken down into amino acids - hcl in stomach distort protein interactions, enzyme secretions typsin and pepsin break protein down. futher broken down by the pancreatic enzyme secretion. amino acids and dipeptides remain and enter jujenum. here they are absorbed into the blood stream via the aid of peptidases- and dipepetides some are broken down further by cytoplasmic peptidases. amino acids enter blood stream and so do some dipeptides. tranported to liver via hepatic portal vein.

Question 32

what enzymes break down protein?

Answer 32

typsin

pepsin

Question 33

what is hypoglycemia

Answer 33

fall in glucose levels

Question 34

what is hyperglycemia

Answer 34

increase in blood glucose levels.